1. Field of the Invention
The invention relates to an igniter for an explosive charge.
2. Description of the Prior Art
In the oil industry, samples of the formations traversed by a bore hole are obtained for purposes of analysis. This is done by lowering a special tool into the bore hole to obtain core samples. In one embodiment, the tool comprises a plurality of core sampling members which are fired outward into the formations to obtain the core samples. Explosive charges set off by igniters are employed to fire the sampling members into the formation. Due to the structure of one type of tool, the igniters are exposed to the high pressure and temperature of the bore hole. In many cases, this high pressure and temperature destroys the igniters or prematurely sets them off resulting in unreliability.